This is most essential with security related application. I've been deploying 433Mhz alarm panels for many years and the issue is not being able to catch the sensors going down (broken or battery issue) right away which poses a security concern.
Thus, I need a way to make sure that I am alerted if a sensor goes offline (specially door, motion, and other sensors). The alerting part can be a sound or TTS speak command, or whatever works. But it's the monitoring part that seems to be the challenge here.
So what's the best way/approach for monitoring in near real-time? - or at least within the day that the issue occurred. What we're trying to avoid is going on for days with the contact sensors or motion sensors not working.
I noticed that most sensors communicate their battery levels at various intervals and perhaps a rule can be created if BATT LEVELS < 20% but this is not "reliable" because there are other ways for a device to go "down" (breaking, lost signal , etc)
What I would love is for all these devices to constantly report to the hub and the hub having an internal monitor with tolerance setting where
"IF DEVICE X DOES NOT REPORT TO HUB IN Y MINUTES, THEN DO ALERT"
if the HUB doesn't have this functionality, is there a way i can create a web application that can poll these devices? (im a web app developer using PHP) .. if there's a way my web app (cron job) can trigger HUB to check for device statuses and get response from HUB, then i can do wonders with it. (But i do need the Hub to cooperate)
So, I dunno how to approach this or if this is even possible. Ya'll got any ideas?
My understanding is that a hub cannot always dictate the reporting period for devices or poll their status, some report only when they have something to report. This is more a case for sensors, devices like lights can be "tested" by turning them on / off to test communications.
Thanks for noting the sleepyness of some devices. but is this by design, depending on the device? I dont mind some devices being sleepy like light bulbs, we will know if they stopped working when we use them. My main concern is for security related devices (door sensors, motion sensors, sirens, etc)
Sensors placed in areas where there are lots of movements and doors opening and closing will definitely report status, so i think i'm in the clear for those. But sensors placed in say, inside a storage unit, or in the attic, or in places where it will not expect activity for a long time, will definitely need to not be "sleepy".
In lined with this, I just thought of getting door or motion sensors with extra features like temperature monitor that would ensure device will be reporting at specific intervals... but then realized a few major downsides:
Cost is much higher
Battery wont last as long
Choices will be limited (right now im playing with cheap and basic Zigbee Sonoff door and motion sensors)
I think you're essentially on the mark with your assumptions / questions. The one's that are typically sleepy are the battery powered devices, like @thebearmay indicated. But as you say, if they have something to report, like temperature swings, then yes, those that report temperature or are triggered often, will for that reason report back more often.
In terms of battery life and alike, I have Smartthings multi-purpose sensors (now produced by Aeotec) on most doors and windows and, depending on different factors can get anywhere from 6-18 months of battery life for a CR2450 coin battery. So it does become expensive the more of these you add. The condition of your mesh can also play a part in the battery drain, if the sensors are having trouble communicating back to base, it can significantly drain the battery. So for those low-use areas or those that do not have good coverage for the protocol you choose, you may want to look at mains powered options, not something I am familiar with myself.